LIGO/Virgo S200224ca
GCN Circular 27524
Subject
LIGO/Virgo S200224ca: Swift XRT observations, 8 X-ray sources
Date
2020-04-10T13:13:23Z (6 years ago)
From
Kim Page at U.of Leicester <klp5@leicester.ac.uk>
P.A. Evans (U. Leicester), J.A. Kennea (PSU), A. Tohuvavohu (U.
Toronto), S.D. Barthelmy (NASA/GSFC), A.P. Beardmore (U. Leicester),
M.G. Bernardini (INAF-OAB), A.A. Breeveld (UCL-MSSL), P. Brown (TAMU),
D.N. Burrows (PSU), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC), G.
Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB),
V. D'Elia(ASDC), S.W.K. Emery (UCL-MSSL), P. Giommi (ASI), C. Gronwall
(PSU), D. Hartmann (U. Clemson), H.A. Krimm (CRESST/GSFC/USRA), N.J.
Klingler (PSU), N.P.M. Kuin (UCL-MSSL), A.Y. Lien (GSFC/UMBC), F.E.
Marshall (NASA/GSFC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), S.R.
Oates (U. Birmingham), P.T. O'Brien (U. Leicester), J.P. Osborne (U.
Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), M.J.Page
(UCL-MSSL), D.M. Palmer (LANL), M. Perri (ASDC), J.L. Racusin
(NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU), M.H. Siegel (PSU), G.
Tagliaferri (INAF-OAB), E. Troja (NASA/GSFC/UMCP) report on behalf of
the Swift team:
Swift has carried out 675 observations of the LVC error region for the
GW trigger S200224ca convolved with the 2MPZ catalogue (Bilicki et al.
2014, ApJS, 210, 9), using the 'bayestar' (version 1) GW localisation
map. As this is a 3D skymap, galaxy distances were taken into account
in selecting which ones to observe. The observations currently span
from 21 ks to 1542 ks after the LVC trigger, and the XRT has covered
64.5 deg^2 on the sky (corrected for overlaps). This covers 81% of the
probability in the 'LALInference' (version 1) skymap, and 79% after
convolving with the 2MPZ galaxy catalogue, as described by Evans et al.
(2016, MNRAS, 462, 1591). These pointings and associated metadata have
been reported to the Treasure Map (Wyatt et al., arXiv 2001.00588;
http://treasuremap.space/alerts?graceids=S200224ca).
We have detected 8 X-ray sources. Each source is assigned a rank of 1-4
which describes how likely it is to be related to the GW trigger, with
1 being the most likely and 4 being the least likely. The ranks are
described at https://www.swift.ac.uk/ranks.php.
We have found:
* 0 sources of rank 1
* 0 sources of rank 2
* 2 sources of rank 3
* 6 sources of rank 4
RANK 3 sources
==============
These are uncatalogued X-ray sources, however they are not brighter
than previous upper limits, so do not stand out as likely counterparts
to the GW trigger.
| Source ID | RA | Dec | Err90 |
| S200224ca_X5 | 11h 35m 31.08s | -12d 42' 10.0" | 6.3" |
| S200224ca_X9 | 11h 37m 19.09s | -04d 43' 59.6" | 6.2" |
RANK 4 sources
==============
These are catalogued X-ray sources, showing no signs of outburst
compared to previous observations, so they are not likely to be related
to the GW trigger.
| Source ID | RA | Dec | Err90 |
| S200224ca_X1 | 11h 42m 19.04s | -14d 22' 38.7" | 5.2" |
| S200224ca_X3 | 11h 35m 55.12s | -11d 42' 24.8" | 5.9" |
| S200224ca_X4 | 10h 50m 7.75s | +11d 32' 31.0" | 4.5" |
| S200224ca_X7 | 11h 41m 41.71s | -14d 07' 50.2" | 5.2" |
| S200224ca_X8 | 11h 25m 51.91s | -07d 42' 25.5" | 5.1" |
| S200224ca_X10 | 11h 52m 3.55s | -11d 22' 21.8" | 4.7" |
The Swift-XRT observations also covered the locations of 13 sources
reported by other observers, thus:
* AT2020dlp (GCN27227) F < 4.1x10^-12 erg cm^-2 s^-1.
* AT2020dlt (GCN27227) F < 4.2x10^-12 erg cm^-2 s^-1.
* AT2020dlu (GCN27227) F < 4.4x10^-12 erg cm^-2 s^-1.
* AT2020dlv (GCN27227) F < 2.9x10^-12 erg cm^-2 s^-1.
* AT2020dlw (GCN27227) F < 2.5x10^-12 erg cm^-2 s^-1.
* AT2020dmb (GCN27227) F < 4.1x10^-12 erg cm^-2 s^-1.
* AT2020dmc (GCN27227) F < 4.1x10^-12 erg cm^-2 s^-1.
* AT2020dme (GCN27227) F < 2.4x10^-12 erg cm^-2 s^-1.
* AT2020dmg (GCN27227) F < 3.9x10^-12 erg cm^-2 s^-1.
* AT2020dmh (GCN27227) F < 4.6x10^-12 erg cm^-2 s^-1.
* AT2020dmi (GCN27227) F < 2.0x10^-13 erg cm^-2 s^-1.
* AT2020dmj (GCN27227) F < 3.4x10^-12 erg cm^-2 s^-1.
* AT2020dmk (GCN27227) F < 2.8x10^-12 erg cm^-2 s^-1.
Flux limits are 3-sigma upper limits on the 0.3-10 keV observed flux.
For all flux conversions and comparisons with catalogues and upper
limits from other missions, we assumed a power-law spectrum with
NH=3x10^20 cm^-2, and photon index (Gamma)=1.7
The results of the XRT automated analysis, including details of the
sources listed above, are online at
https://www.swift.ac.uk/LVC/S200224ca
This circular is an official product of the Swift XRT team.
GCN Circular 27483
Subject
LIGO/Virgo S200224ca: Upper limits from Konus-Wind observations
Date
2020-04-03T22:13:46Z (6 years ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
A. Ridnaia, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline,
on behalf of the Konus-Wind team, report:
Konus-Wind (KW) was observing the whole sky at the time of the
LIGO/Virgo event S200224ca (2020-02-24 22:22:34.406 UTC, hereafter T0;
LIGO/Virgo Collaboration GCN Circ. 27184).
No triggered KW GRBs happened between ~17 hours before and ~3 days
after T0. Using waiting-mode data within the interval T0 +/- 100 s,
we found no significant (> 5 sigma) excess over the background
in both KW detectors on temporal scales from 2.944 s to 100 s.
We estimate an upper limit (90% conf.) on the 20 - 1500 keV fluence
to 8.3x10^-7 erg/cm^2 for a burst lasting less than 2.944 s and having a
typical KW short GRB spectrum (an exponentially cut off power law with
alpha =-0.5 and Ep=500 keV). For a typical long GRB spectrum (the Band
function with alpha=-1, beta=-2.5, and Ep=300 keV), the corresponding
limiting peak flux is 2.7x10^-7 erg/cm^2/s (20 - 1500 keV, 2.944 s scale).
All the quoted values are preliminary.
GCN Circular 27366
Subject
LIGO/Virgo S200224ca: DESGW Summary of DECam Observations
Date
2020-03-11T20:39:09Z (6 years ago)
From
Robert Morgan at U. of Wisconsin-Madison <robert.morgan@wisc.edu>
Robert Morgan (Univ. Wisconsin-Madison), Antonella Palmese (Fermilab), Alyssa Garcia (Brandeis Univ.), Marcelle Soares-Santos (Brandeis Univ.), Ken Herner (Fermilab), Clecio R. Bom (CBPF), Constantina Nicolaou (University College London), Kathy Vivas (NSF�s OIR Lab), Alfredo Zenteno (NSF�s OIR Lab), and Juan Garcia-Bellido (IFT-UAM) on behalf of the DESGW Collaboration*.
We triggered the Dark Energy Camera (DECam) at Cerro Tololo Inter-American Observatory in Chile on the localization area of the binary-black-hole merger event detected by LIGO Livingston, LIGO Hanford, and Virgo (S200224ca, GCN 27184). Observations took place on 2020-02-24, 2020-02-25, 2020-02-27, and 2020-03-05 in the i-band and reached 10-sigma limiting magnitudes of 23.17, 23.19, 23.49, and 23.03 respectively. Each night, the area was covered twice and images on the same night were coadded to increase our depth.
We determined interesting candidates from our observations by selecting sources not present in archival DECam images, requiring a detection in both exposures on 2020-02-24, requiring that if redshift information exists for the host galaxy that it be consistent with the LVC distance posterior assuming a standard cosmological model, that the candidate have at least one autoscan (Goldstein 2015) score > 0.7 for image artifact rejection, and that the object not be detected on 2020-03-05. We also removed objects listed as variable stars in the GAIA DR2 catalog, and visually inspected the images. All DECam candidates in GCN 27227 were rejected by the required non-detection on 2020-03-05 (i.e., they are consistent with supernovae).
After completing our follow-up, we find 8 interesting transient objects and document them below. Each object was detected on 2020-02-24, too faint to detect in our observations on 2020-03-05, and it was visually matched to a host galaxy.
TNS ID | DESGW NAME | RA | DEC | BRIGHTEST MAG_i
2020eho | desgw-200224-aa | 173.542273 | -11.413514 | 23.35 +/- 0.12
2020ehp | desgw-200224-ab | 177.589350 | -9.9630310 | 22.63 +/- 0.09
2020ehq | desgw-200224-ac | 174.445462 | -10.039503 | 23.01 +/- 0.18
2020ehr | desgw-200224-ad | 172.931711 | -4.1346680 | 22.76 +/- 0.10
2020eht | desgw-200224-ae | 177.718160 | -10.190816 | 23.18 +/- 0.11
2020ehv | desgw-200224-af | 175.921426 | -6.8633130 | 22.78 +/- 0.11
2020ehw | desgw-200224-ag | 175.770071 | -6.2421670 | 22.88 +/- 0.11
2020ehy | desgw-200224-ah | 176.700106 | -11.848473 | 23.08 +/- 0.12
Candidates with a host galaxy in DESI imaging (Dey et al. 2019), SDSS or 2MASS have host galaxy properties tabulated below:
TNS ID | DESGW NAME | HOST ID | HOST RA | HOST DEC | HOST SEP (") | HOST MAG_i | Host Redshift | SOURCE
2020eht | desgw-200224-ad | 1237671129660261003 | 172.928529 | -4.135549 | 11.86 | 19.67 | 0.31 +/- 0.13 | SDSS
2020ehv | desgw-200224-af | -- | 175.920943 | -6.864041 | 3.14 | -- | 0.2754 +/- 0.045 | DESI imaging
The DESI imaging redshifts are the photometric redshifts from Zhou et al. (2020).
*The DESGW Collaboration:
Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D�Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO)
GCN Circular 27293
Subject
LIGO/Virgo S200224ca: No counterpart candidates in TOROS observations
Date
2020-03-03T01:57:38Z (6 years ago)
From
Richard Camuccio at TOROS <rcamuccio@gmail.com>
Mario Diaz (UTRGV/CGWA), Diego Garcia Lambas (IATE), Lucas Macri (TAMU),
Jose Luis Nilo Castellon (Univ La Serena), Omar Lopez-Cruz (UNAM)
Richard Camuccio (UTRGV/CGWA), Martell Valencia (UTRGV/CGWA), Victor Perez
(UTRGV/CGWA), Wahltyn Rattray (UTRGV/CGWA) are reporting on behalf of the
TOROS collaboration.
We report the following targeted observations in response to S200224ca
conducted by
the Cristina Torres Memorial Observatory (CTMO) in Brownsville, Texas:
SDSS J113309.58-085247.9, RA: 173.289917 deg, Dec: -8.879995 deg
SDSS J113813.09-113309.0, RA: 174.558000 deg, Dec: -11.552510 deg
SDSS J113817.07-113633.2, RA: 174.574000 deg, Dec: -11.609180 deg
SDSS J113440.11-074557.5, RA: 173.667145 deg, Dec: -7.765990 deg
Observations were conducted on 2020-02-25 from 04:00 to 06:00 UT and
2020-03-01 from 04:00 to 09:00 UT using the CTMO CDK17 optical astrograph
and ProLine 16803 CCD camera (43 arcminute FOV). For 02-25 observations, we
took 10x30-second exposures in SDSS u'-band at 1x1 binning. For 03-01
observations, we took 15x60-second unfiltered exposures at 2x2 binning.
Source search is ongoing and we will report any positive transient
detection.
GCN Circular 27288
Subject
LIGO/Virgo S200224ca: Transient found in Swift/UVOT counterpart search
Date
2020-03-02T17:34:15Z (6 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (MSSL-UCL), S. R. Oates (U. Birmingham), F. E. Marshall (NASA/GSFC), N. P. M. Kuin
(UCL-MSSL), P. Brown (TAMU), C. Gronwall (PSU), M.J. Page (UCL-MSSL), M. De Pasquale (Istanbul U.),
M. H. Siegel (PSU), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), S. D. Barthelmy (NASA/GSFC), A.
P. Beardmore (U. Leicester), D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC), G.
Cusumano (INAF-IASF PA), V. D'Elia(ASDC), P. A. Evans (U. Leicester), P. Giommi (ASI), D. Hartmann
(Clemson U.), J. A. Kennea (PSU), N. J. Klingler (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC),
D. B. Malesani (DTU Space), A. Melandri (INAF-OAB), J. A. Nousek (PSU), P. T. O'Brien (U.
Leicester), J. P. Osborne (U. Leicester), C. Pagani (U. Leicester), K. L. Page (U.Leicester), D.M.
Palmer (LANL), M. Perri (ASDC), J. L. Racusin (NASA/GSFC), T. Sakamoto (AGU), B. Sbarufatti
(INAF-OAB/PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (U Toronto), and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift team:
We report a transient found in the UVOT search results of the LVC event S200224ca (LIGO/VIRGO
Collaboration GCN Circ. 27184).
On 2020-02-25 at 16:05:25 UT Swift UVOT took a 75s exposure, 63.7ks after the GW trigger, in the u
band (exposure ID uu604339530, target ID 07031750) which showed a source that had brightened
significantly compared with archival images/catalogues. The source is not seen in the DSS, is not
listed in the Gaia DR2, 2MASS or GSC2.3 catalogues and is not listed as a minor planet. However, a
source is seen at this position in the Pan-STARRS catalogue (id 94241765879572233) with imag=21.6,
and in VISTA (id 473452322969).
The position is:
RA = 176.58794 deg
Dec = -11.46508 deg
which is RA=11:46:21.11, Dec=-11:27:54.3 (J2000).
The magnitude using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373)
is u=18.6 +/- 0.2 mag (Vega). In a followup observation with all filters, 275ks after the GW
trigger, the object had faded to u>19.6 mag, with upper limits in all filters.
Filter Date-obs Exp(s) Mag
u 2020-02-25T16:05:25 75 18.6 +/- 0.2
v 2020-02-28T02:44:02 334 >19.5
b 2020-02-28T02:48:35 122 >19.9
u 2020-02-28T02:47:27 143 >19.6
w1 2020-02-28T02:46:19 307 >19.7
m2 2020-02-28T02:45:10 333 >19.7
w2 2020-02-28T02:42:54 333 >19.9
No source is found at this position in the XRT, with a 3-sigma upper limit of 4.75 x 10-3 s^-1
which corresponds to a 0.3-10 keV observed flux of 1.9e-13 erg cm^-2 s^-1.
At this position, the distance estimate from the LALInference sky map has a mean of 1556.46 Mpc with
a sigma of 320.357 Mpc.
This circular is an official product of the Swift team.
GCN Circular 27262
Subject
LIGO/Virgo S200224ca: Updated Sky Localization and EM Bright Classification
Date
2020-02-28T18:24:40Z (6 years ago)
From
Vinaya Valsan at U. of Wisconsin Milwaukee <vvalsan@uwm.edu>
The LIGO Scientific Collaboration and the Virgo Collaboration report:
We have conducted further analysis of the LIGO Hanford Observatory
(H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1)
data around the time of the compact binary merger (CBC) candidate
S200224ca (GCN Circular 27184). Parameter estimation has been
performed using LALInference [1] and a new sky map,
LALInference.fits.gz,1, distributed via GCN Notice, is available for
retrieval from the GraceDB event page:
https://gracedb.ligo.org/superevents/S200224ca
The preferred sky map at this time is LALInference.fits.gz,1. For the
LALInference.fits.gz,1 sky map, the 90% credible region is 72 deg2.
Marginalized over the whole sky, the a posteriori luminosity distance
estimate is 1575 +/- 322 Mpc (a posteriori mean +/- standard
deviation).
Based on posterior support from parameter estimation [1], under the
assumption that the candidate S200224ca is astrophysical in origin,
the probability that the lighter compact object has a mass < 3 solar
masses (HasNS) is <1%. Using the masses and spins inferred from the
signal, the probability of matter outside the final compact object
(HasRemnant) is <1%.
For further information about analysis methodology and the contents
of this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https://emfollow.docs.ligo.org/userguide/>.
[1] Veitch et al. PRD 91, 042003 (2015)
GCN Circular 27238
Subject
LIGO/Virgo S200224ca : No significant candidates in TAROT - FRAM - GRANDMA observations
Date
2020-02-27T13:17:57Z (6 years ago)
From
Tatyana Sadibekova at AIM-CEA Saclay <tatyana.sadibekova@cea.fr>
T. Sadibekova (AIM-CEA), H. Crisp (OzGrav-UWA), P. Hello (IJCLab),
Z. Vidadi (SHAO), (FZU), M. Boer (Artemis), N. Christensen (Artemis),
L. Eymar (Artemis), S. Karpov (FZU), A. Klotz (IRAP), M. Masek (FZU),
K. Noysena (Artemis, IRAP), S. Antier (APC), A. Coleiro (APC), D. Corre
(IJCLab), M. Coughlin (UMN), D. Coward (OzGrav-UWA), J.G. Ducoin
(IJCLab), B. Gendre (OzGrav-UWA), D. A. Kann (HETH/IAA-CSIC),
N. Kochiashvili (Iliauni), C. Lachaud (APC), N. Leroy (IJCLab),
C. Thoene (HETH/IAA-CSIC), D. Turpin (AIM-CEA), X. Wang (THU)
report on behalf of the FRAM, TAROT and GRANDMA collaborations.
We performed tiled observations of LIGO/Virgo S200224ca event with the
FRAM-Auger, FRAM-CTA-N, TAROT-Calern (TCA), TAROT-Chili (TCH), TAROT-
Reunion (TRE) telescopes.
FRAM-Auger is located at Pierre Auger Observatory. FRAM-CTA-N is
located at Observatorio del Roque de los Muchachos. TCA is located at
Calern site at the Cote d'Azur observatory. TCH is located at La Silla
ESO observatory (LaS/ESO). TRE is located at Les Makes astronomical
observatory.
The following table shows for each telescope: the delay in minutes
from the trigger, which filter is used, the field of view of the
telescope in degrees and the typical limiting magnitude (AB mag) for a
given exposure in seconds (s).
+-------------+---------+----------+-------------+------------+
| Telescope | Delay | Filter | f.o.v. | Limiting |
| | [min] | | [deg] | Mag. |
|-------------+---------+----------+-------------+------------|
| FRAM-Auger | 415 | R | 1.0 x 1.0 | 18.0 (60s) |
| FRAM-CTA-N | 20 | R | 0.45 x 0.45 | 17.0 (90s) |
| TCA | 15 | Clear | 1.9 x 1.9 | 18.0 (60s) |
| TCH | 301 | Clear | 1.9 x 1.9 | 18.0 (60s) |
| TRE | 47 | Clear | 4.2 x 4.2 | 17.0 (60s) |
+-------------+---------+----------+-------------+------------+
We performed the following joint tiled observations [1] :
+-------------+------------+------------+---------+---------+---------+
| Telescope | TStart | TEnd | RA | DEC | Proba |
| | [UTC] | [UTC] | [deg] | [deg] | [%] |
|-------------+------------+------------+---------+---------+---------|
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 175.082 | -9.243 | 3.7 |
| | 05:16:43 | 05:21:10 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 175.562 | -10.216 | 3.7 |
| | 05:21:47 | 05:26:13 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 175.055 | -11.189 | 4.0 |
| | 05:26:48 | 05:31:15 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 174.575 | -10.216 | 3.9 |
| | 05:31:51 | 05:36:18 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 174.605 | -8.270 | 3.4 |
| | 05:36:54 | 05:41:21 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 176.044 | -11.189 | 3.4 |
| | 05:42:12 | 05:46:39 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 174.098 | -9.243 | 3.5 |
| | 05:47:13 | 05:51:40 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 176.022 | -12.162 | 3.2 |
| | 05:52:18 | 05:56:45 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 174.130 | -7.297 | 2.8 |
| | 05:57:20 | 06:01:47 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 173.624 | -8.270 | 3.0 |
| | 06:02:25 | 06:06:51 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 175.028 | -12.162 | 2.7 |
| | 06:20:49 | 06:30:32 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 176.066 | -9.243 | 2.1 |
| | 06:31:07 | 06:35:34 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 175.586 | -8.270 | 2.0 |
| | 06:36:08 | 06:40:35 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 173.152 | -7.297 | 2.2 |
| | 06:41:12 | 06:45:39 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 176.510 | -13.135 | 2.3 |
| | 06:46:17 | 06:50:44 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 174.130 | -6.324 | 1.9 |
| | 06:51:22 | 06:55:49 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 176.548 | -10.216 | 1.9 |
| | 06:56:25 | 07:00:52 | | | |
| FRAM-Auger | 2020-02-25 | 2020-02-25 | 174.066 | -11.189 | 2.2 |
| | 07:01:27 | 07:05:54 | | | |
| ----- | ----- | ----- | ----- | ----- | ----- |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 174.905 | -9.823 | 0.9 |
| | 22:41:52 | 22:45:58 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 175.336 | -10.260 | 0.9 |
| | 22:46:12 | 22:50:18 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 174.690 | -9.387 | 0.9 |
| | 22:50:32 | 22:54:38 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 175.348 | -9.823 | 0.9 |
| | 22:54:52 | 22:58:58 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 174.779 | -10.260 | 0.9 |
| | 22:59:11 | 23:03:17 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 175.553 | -10.697 | 0.9 |
| | 23:03:32 | 23:07:38 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 174.995 | -10.697 | 0.9 |
| | 23:07:51 | 23:11:57 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 175.212 | -11.134 | 0.9 |
| | 23:12:16 | 23:16:22 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 175.657 | -11.134 | 0.9 |
| | 23:16:42 | 23:20:48 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 174.461 | -9.823 | 0.9 |
| | 23:21:03 | 23:25:09 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 174.591 | -8.513 | 0.8 |
| | 23:25:28 | 23:29:35 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 174.247 | -9.387 | 0.8 |
| | 23:34:14 | 23:38:20 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 175.133 | -9.387 | 0.8 |
| | 23:38:34 | 23:42:40 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 174.693 | -8.950 | 0.7 |
| | 23:43:00 | 23:47:06 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 175.429 | -11.571 | 0.8 |
| | 23:47:27 | 23:51:33 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-24 | 174.149 | -8.513 | 0.8 |
| | 23:51:53 | 23:55:59 | | | |
| FRAM-CTA-N | 2020-02-24 | 2020-02-25 | 175.875 | -11.571 | 0.8 |
| | 23:56:15 | 00:00:21 | | | |
| FRAM-CTA-N | 2020-02-25 | 2020-02-25 | 174.377 | -8.076 | 0.7 |
| | 00:00:51 | 00:04:57 | | | |
| FRAM-CTA-N | 2020-02-25 | 2020-02-25 | 175.135 | -8.950 | 0.7 |
| | 00:05:11 | 00:09:17 | | | |
| ----- | ----- | ----- | ----- | ----- | ----- |
| TCA | 2020-02-24 | 2020-02-27 | 170.656 | -8.825 | 0.3 |
| | 22:37:11 | 00:35:59 | | | |
| TCA | 2020-02-24 | 2020-02-27 | 172.453 | -13.012 | 0.2 |
| | 22:49:55 | 00:42:44 | | | |
| TCA | 2020-02-24 | 2020-02-26 | 179.075 | -11.156 | 0.2 |
| | 22:56:39 | 22:19:30 | | | |
| TCA | 2020-02-25 | 2020-02-25 | 172.642 | 0.022 | 0.2 |
| | 00:53:10 | 20:59:30 | | | |
| ----- | ----- | ----- | ----- | ----- | ----- |
| TCH | 2020-02-25 | 2020-02-25 | 174.965 | -10.000 | 13.6 |
| | 03:23:32 | 08:29:47 | | | |
| TCH | 2020-02-25 | 2020-02-26 | 173.064 | -11.343 | 2.5 |
| | 03:34:04 | 09:42:58 | | | |
| TCH | 2020-02-25 | 2020-02-26 | 171.384 | -0.909 | 0.8 |
| | 03:49:52 | 07:25:08 | | | |
| TCH | 2020-02-25 | 2020-02-27 | 178.600 | -14.505 | 1.0 |
| | 08:38:18 | 00:42:33 | | | |
| TCH | 2020-02-25 | 2020-02-26 | 178.619 | -12.686 | 0.9 |
| | 08:44:37 | 09:45:10 | | | |
| TCH | 2020-02-25 | 2020-02-26 | 170.827 | -7.232 | 0.7 |
| | 08:58:03 | 09:21:08 | | | |
| TCH | 2020-02-26 | 2020-02-26 | 174.143 | -1.777 | 0.2 |
| | 00:53:49 | 08:47:05 | | | |
| TCH | 2020-02-26 | 2020-02-26 | 174.618 | -3.595 | 0.7 |
| | 02:41:32 | 09:19:02 | | | |
| TCH | 2020-02-26 | 2020-02-26 | 175.020 | -5.414 | 2.1 |
| | 04:16:46 | 07:04:56 | | | |
| ----- | ----- | ----- | ----- | ----- | ----- |
| TRE | 2020-02-24 | 2020-02-26 | 175.909 | -4.091 | 3.0 |
| | 23:08:49 | 00:02:00 | | | |
| TRE | 2020-02-25 | 2020-02-25 | 175.814 | -12.273 | 33.5 |
| | 18:30:11 | 18:36:33 | | | |
| TRE | 2020-02-25 | 2020-02-26 | 173.793 | -8.182 | 36.5 |
| | 23:23:32 | 01:06:18 | | | |
| TRE | 2020-02-25 | 2020-02-26 | 171.818 | -4.091 | 9.7 |
| | 23:36:44 | 19:42:42 | | | |
| TRE | 2020-02-26 | 2020-02-26 | 177.931 | -8.182 | 5.3 |
| | 01:18:59 | 01:25:16 | | | |
| TRE | 2020-02-26 | 2020-02-26 | 175.714 | -16.364 | 4.1 |
| | 19:49:32 | 19:55:54 | | | |
+-------------+------------+------------+---------+---------+---------+
TStart and TEnd refers respectively to the time of the first and last
exposure for a given tile. Observations are not necessarily continuous
in this interval.
The Probability refers to the 2D spatial probability of the GW skymap
enclosed in a given tile.
These observations cover about 93.3% of the cumulative probability of
the BAYESTAR skymap created on 2020-02-24 22:23:22 (UTC).
The coverage map is available at:
https://grandma-
owncloud.lal.in2p3.fr/index.php/s/XgtMhPRxcyL09gR/download?path=%2F&files=GRANDMA_S200224ca_1582797966.svg
No significant transient candidates were found during our low latency
analysis [2,3].
GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger
Addicts) is a network of robotic telescopes connected all over the
world with both photometry and spectrometry capabilities for Time-
domain Astronomy [2](https://grandma.lal.in2p3.fr/).
Details on the different telescopes are available on the GRANDMA web
pages.
[1] M. W Coughlin et al., MNRAS 2019, https://doi.org/10.1093/mnras/stz2485
[2] S. Antier et al., MNRAS 2019, https://doi.org/10.1093/mnras/stz3142
[3] K. Noysena et al., ApJ 2019, arXiv:1910.02770
GCN Circular 27231
Subject
LIGO/Virgo S200224ca: Upper limits from CALET observations.
Date
2020-02-27T05:53:24Z (6 years ago)
From
Yuta Kawakubo at Louisiana State U./CALET <kawakubo1@lsu.edu>
Y. Kawakubo (LSU), A. Yoshida, T. Sakamoto, V. Pal'shin,
S. Sugita (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:
At the trigger time of the compact binary merger candidate
S200224ca T0 = 2020-02-24 22:22:34.406 UT (The LIGO
Scientific Collaboration and Virgo Collaboration, GCN
Circ. 27184), the CALET Gamma-ray Burst Monitor (CGBM)
high voltages were off (from T0-18 min to T0+1 min).
The CALET Calorimeter (CAL) was operating in the high
energy trigger mode at the trigger time of S200224ca. Using
the CAL data, we have searched for gamma-ray events in the
10-100 GeV band from -60 sec to +60 sec from the GW trigger
time and found no candidates in the overwrap region with the
LIGO-Virgo high probability localization region. The 90%
upper limit of CAL is 5.0 x 10^-7 erg/cm^2/s (10-100 GeV)
when the summed LIGO-Virgo probability reaches 95%. The CAL
FOV was centered at RA = 167.5 deg, DEC = -24.8 deg at T0.
GCN Circular 27227
Subject
LIGO/Virgo S200224ca: DESGW Optical counterpart candidates from DECam
Date
2020-02-26T18:36:54Z (6 years ago)
From
Robert Morgan at U. of Wisconsin-Madison <robert.morgan@wisc.edu>
Robert Morgan (Univ. Wisconsin-Madison), Alyssa Garcia (Brandeis Univ.), Marcelle Soares-Santos (Brandeis Univ.), Ken Herner (Fermilab), Clecio R. Bom (CBPF), Antonella Palmese (Fermilab), Megan Tabbutt (Univ. Wisconsin-Madison), Katelyn Stringer (Texas A&M Univ.), Kathy Vivas (NSF�s OIR Lab), Alfredo Zenteno (NSF�s OIR Lab), Thomas Puzia (Pontificia Universidad Cat�lica de Chile), and Eric Peng (Peking Univ.) on behalf of the DESGW Collaboration*.
We triggered the Dark Energy Camera (DECam) at Cerro Tololo Inter-American Observatory in Chile on the localization are of the binary-black-hole merger event detected by LIGO Livingston, LIGO Hanford, and Virgo (S200224ca, GCN 27184). Observations began at 06:30 UT and lasted 72 minutes, during which time we covered the entire 50% localization area and most of the 90% localization area. We took 90 second i band exposures and repeated coverage of the area a second time to rule out moving objects. These observations reached an 10 sigma i band limiting magnitude of 22.64 mag.
We determined interesting candidates from our observations by selecting sources not present in archival DECam images, requiring a detection in both exposures, requiring that if redshift information exists for the host galaxy that it be consistent with the LVC distance posterior assuming a standard cosmological model, and that the candidate have at least one autoscan (Goldstein 2015) score > 0.88 for image artifact rejection. We also removed objects listed as variable stars in the GAIA DR2 catalog, and visually inspected the images.
The candidates from our first night of observations are tabulated below:
TNS ID | DESGW NAME | RA | DEC | MAG_i
2020dlp | desgw-200224-e | 173.37895 | -11.375735 | 21.83 +/- 0.04
2020dlt | desgw-200224-i | 172.183856 | -7.852997 | 21.47 +/- 0.05
2020dlu | desgw-200224-j | 177.633327 | -11.562617 | 21.07 +/- 0.02
2020dlv | desgw-200224-k | 172.702488 | -11.339593 | 21.76 +/- 0.05
2020dlw | desgw-200224-l | 176.600488 | -10.618643 | 21.71 +/- 0.04
2020dlz | desgw-200224-o | 172.314739 | -11.461327 | 21.94 +/- 0.05
2020dmb | desgw-200224-q | 176.001543 | -13.715623 | 21.71 +/- 0.05
2020dmc | desgw-200224-r | 176.854035 | -9.675706 | 22.28 +/- 0.09
2020dme | desgw-200224-t | 176.664265 | -8.132082 | 22.42 +/- 0.08
2020dmg | desgw-200224-v | 173.216383 | -9.730723 | 22.40 +/- 0.09
2020dmh | desgw-200224-w | 173.520275 | -10.733151 | 22.58 +/- 0.09
2020dmi | desgq-200224-x | 176.640751 | -11.507011 | 22.21 +/- 0.08
2020dmj | desgw-200224-y | 173.771767 | -11.109408 | 22.15 +/- 0.06
2020dmk | desgw-200224-z | 172.877293 | -3.765198 | 22.68 +/- 0.10
Candidates with a host galaxy in SDSS or 2MASS have host galaxy properties tabulated below:
TNS ID | DESGW NAME | HOST ID | HOST RA | HOST DEC | HOST SEP (�) | HOST MAG_i | Host Redshift | SOURCE
2020dlt | desgw-200224-i | 1237671140940252161 | 172.183362 | -7.853086 | 1.79 | 21.47 | 0.188+/- 0.041 | SDSS
Analysis of these candidates is ongoing and spectroscopic characterization is encouraged. More information on these candidates, such as updated host galaxy properties and more photometric observations, is currently being collected.
*The DESGW Collaboration:
Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D�Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO)
GCN Circular 27219
Subject
LIGO/Virgo S200224ca: Upper limits from Insight-HXMT/HE observations
Date
2020-02-26T08:06:44Z (6 years ago)
From
Qi Luo at IHEP <luoqi@ihep.ac.cn>
Q. Luo, Y. G. Zheng, C. Cai, S. Xiao, Q. B. Yi,
Y. Huang, C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong,
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang,
Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin,
Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song,
M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:
Insight-HXMT was taking data normally around the reported LIGO/Virgo
S200224ca event (GCN #27184). At the GW trigger time
2020-02-24T22:22:34.406 UTC (denoted as T0), about 99.6% of the
GW localization region was covered by the Insight-HXMT without
occultation by the Earth.
Within T0 +/- 100 s, no significant excess events (SNR > 3 sigma) are
found in a search of the Insight-HXMT/HE raw light curves.
Assuming the GW counterpart GRB with three typical GRB Band spectral
models, two typical duration timescales (1 s, 10 s) from the center
of the LIGO-Virgo location probability map (RA=174.9 deg, DEC=-9.8 deg),
the 5-sigma upper-limits fluence (0.2 - 5 MeV, incident energy) are
reported below:
Band model 1 (alpha=-1.9, beta=-3.7, Ep=70 keV):
1 s: 1.4e-07 erg cm^-2
10 s: 1.1e-06 erg cm^-2
Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV):
1 s: 2.2e-07 erg cm^-2
10 s: 1.7e-06 erg cm^-2
Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV):
1 s: 6.8e-07 erg cm^-2
10 s: 3.9e-06 erg cm^-2
All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (deposited energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the spacecraft.
GCN Circular 27216
Subject
LIGO/Virgo S200224ca: no counterpart candidates in the Swift/BAT observations
Date
2020-02-26T01:35:06Z (6 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
S. D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
A. P. Beardmore (U. Leicester), M. G. Bernardini (INAF-OAB),
A. A. Breeveld (MSSL-UCL), D. N. Burrows (PSU),
S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC),
G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), V. D'Elia (ASI-ASDC), S. Emery (UCL-MSSL),
P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU),
D. Hartmann (Clemson U.), J. A. Kennea (PSU),
N. Klingler (PSU), H. A. Krimm (NSF),
N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), J. A. Nousek (PSU),
S. R. Oates (U. of Birmingham), P. T. O'Brien (U. Leicester),
J. P. Osborne (U. Leicester), C. Pagani (U. Leicester),
K. L. Page (U.Leicester), M. J. Page (UCL-MSSL), M. Perri (ASDC),
J. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU),
M. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (U. Toronto),
E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team:
We report the search results in the BAT data within T0 +/- 100 s of the
LVC event S200224ca (LIGO/VIRGO Collaboration GCN Circ. 27184),
where T0 is the LVC trigger time (2020-02-24T22:22:34.378 UTC).
The center of the BAT field of view (FOV) at T0 is
RA = 136.122 deg,
DEC = -32.441 deg,
and the roll angle is 204.112 deg.
The BAT FOV (>10% partial coding) covers 88.38% of the integrated
LVC localization probability, and 87.02% of the galaxy convolved
probability (Evans et al. 2016). Note that the sensitivity in the BAT FOV
changes with the partial coding fraction. Please see the BAT FOV figure
in the summary page (link below) for the specific location of the LVC
region relative to the BAT FOV.
Within T0 +/- 100 s, no significant detections (signal-to-noise ratio
>~ 5 sigma) are found in the BAT raw light curves with time bins of 64 ms,
1 s, and 1.6 s. Assuming a short GRB with a typical
spectrum in the BAT energy range (i.e., a simple power-law model with a
power-law index of -1.32, Lien & Sakamoto et al. 2016), the 5-sigma upper
limit in the 1-s binned light curve corresponds to a flux upper
limit (15-350 keV) of ~ 8.56 x 10^-8 erg/s/cm^2 for the 100% coded region
(i.e., for a burst with 0 deg from BAT boresight) and ~ 1.80 x 10^-6
erg/s/cm2
for the 10% coded region (~56 deg from BAT boresight).
Assuming a luminosity of ~ 2 x 10^47 erg/s (similar to GW170817)
and an average Epeak of ~ 400 keV for short GRBs (Bhat et al. 2016),
these flux upper limits corresponds to a distance of ~ 77.68 Mpc (100%
coded)
and ~ 16.93 Mpc (10% coded).
Event data are available from T0+29.042 s to T0+45.176 s via the GUANO
system
(Tohuvavohu et al. 2020, in prep). No significant detections (above our
typical
image threshold of ~ 6.5 to 7 sigma) are found in the 15-350 keV images
created using intervals of the whole event data range.
BAT retains decreased, but significant, sensitivity to rate increases for
gamma-ray events outside of its FOV. About 11.62% of the integrated LVC
localization probability was outside of the BAT FOV but above the
Earth's limb from Swift's location, and the corresponding flux upper limits
for this region are within roughly an order of magnitude higher than those
within the FOV.
The results of the BAT analysis are available at
https://swift.gsfc.nasa.gov/results/BATbursts/team_web/S200224ca/web/source_public.html
GCN Circular 27213
Subject
LIGO/Virgo S200224ca: No counterpart candidates in KAIT observations
Date
2020-02-25T23:06:59Z (6 years ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
Sergiy Vasylyev, Benjamin E. Stahl, Yukei Murakami, Andrew Hoffman,
James Sunseri, Keto D. Zhang, Shaunak Modak, WeiKang Zheng,
and Alexei V. Filippenko (UC Berkeley) report on behalf of
the Lick/KAIT GW follow-up team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, observed the 90% region of the gravitational-wave
event S200224ca (GCN 27184) detected by LIGO/Virgo. More than
one thousand galaxies were selected from the Glade catalog V1.0
(Dalya et al., 2018, MNRAS, 479, 2374; http://aquarius.elte.hu/glade/)
according to their priority score. KAIT observed 77 of them based on
their priority scores and elevation visibility, with each clear-filter
exposure time being 60 s. The first image was taken at 05:01:26, Feb.
25th UT, about 6.7 hours after the trigger, and the last image at
09:29:37 UT. Our typical limiting mag is 19.0. No viable counterparts
were identified and the analysis is ongoing. A full list of galaxies
observed by KAIT is given below.
GladeID UT(Feb25) RA_J2000 Dec_J2000
-----------------------------------------------
G0673461 05:01:26 10:44:53.496 +12:35:05.892
G0698936 05:03:45 10:46:08.2543 +12:36:58.5792
G0629402 05:04:52 10:46:19.801 +12:37:19.56
G0806101 05:06:03 10:46:38.9429 +11:45:55.1124
G0518983 05:07:12 10:47:22.1998 +12:43:49.764
G0165487 05:08:21 10:48:17.6659 +13:54:41.58
G0400195 05:11:48 10:50:23.4156 +13:48:52.2252
G0259691 05:12:57 10:50:42.0482 +12:56:50.2152
G0782778 05:16:27 10:51:08.6683 +13:50:53.7324
G0654615 05:17:37 10:51:09.4445 +08:43:32.2752
G0679827 05:18:46 10:51:11.2975 +10:38:36.2796
G0787037 05:19:56 10:51:16.5161 +11:51:47.2824
G0619835 05:21:08 10:51:19.9915 +11:49:29.28
G0591424 05:22:17 10:51:29.4984 +10:41:08.4408
G0669021 05:26:59 10:51:43.3375 +10:45:24.4728
G0200654 05:28:09 10:51:46.8823 +08:46:31.476
G0583050 05:29:18 10:51:59.0551 +12:12:55.4868
G0556324 05:30:28 10:52:11.4074 +12:17:48.462
G1138356 05:31:37 10:52:32.9772 +10:36:20.5128
G0660070 05:32:46 10:52:48.241 +10:41:31.4772
G0626622 05:33:56 10:52:49.4347 +12:07:44.472
G0787922 05:35:05 10:52:59.4288 +10:12:38.772
G0628137 05:45:32 10:53:02.8565 +11:31:16.7772
G0296593 05:46:41 10:53:03.7097 +09:37:24.7764
G0709189 05:47:51 10:53:53.7487 +12:37:21.27
G0619660 05:49:00 10:54:09.1882 +12:33:24.2856
G0749789 05:50:09 10:54:17.19 +10:48:55.7316
G0841361 05:51:19 10:54:17.6844 +09:18:30.7332
G0828471 05:52:28 10:54:49.2773 +09:11:04.362
G0884104 05:53:37 10:54:59.8829 +09:11:26.3724
G1295231 05:54:46 10:55:00.8275 +12:02:53.3724
G0565461 05:55:56 10:55:23.4559 +11:18:59.256
G0549630 05:57:05 10:55:31.9044 +08:50:49.2648
G0093456 05:58:15 10:55:36.1524 +08:23:18.2688
G0569013 05:59:24 10:55:38.1408 +11:00:20.268
G0623088 06:00:34 10:55:53.6388 +15:20:27.3624
G0790896 06:01:43 10:56:06.8554 +10:58:22.6344
G0608596 06:02:53 10:56:15.487 +09:45:15.6168
G0280245 06:04:02 10:56:17.2303 +09:33:57.384
G1005344 06:05:16 10:56:39.4006 +07:07:20.4168
G0602699 06:06:25 10:56:44.0772 +09:45:32.4144
G0624595 06:07:34 10:56:44.1686 +07:09:04.4172
G1069807 06:08:44 10:57:07.2144 +10:20:32.892
G1163532 06:09:53 10:57:15.2381 +07:47:24.882
G1337604 06:11:02 10:57:23.5034 +08:49:37.1748
G0827745 06:12:12 10:57:31.8641 +08:17:56.1768
G1228502 06:13:21 20:11:20.7934 +69:57:42.7824
G0565601 08:55:53 10:59:10.1551 +07:48:32.2776
G0782794 08:57:02 10:59:18.175 +12:18:46.7856
G0743465 08:58:14 10:59:33.2189 +07:41:03.3288
G0682241 08:59:24 10:59:53.4706 +08:54:27.2052
G0791401 09:00:33 11:00:12.3888 +08:46:15.7584
G0797621 09:01:40 11:00:22.716 +08:20:17.7756
G0565575 09:02:50 11:00:31.4026 +07:16:16.7808
G0632512 09:03:59 11:00:33.6144 +06:12:13.7808
G0564972 09:05:08 11:00:40.8362 +07:13:24.7512
G0549831 09:06:17 11:01:01.9373 +07:16:50.7612
G0587079 09:07:27 11:02:43.7878 +05:22:52.5036
G0745333 09:08:36 11:05:26.3818 +03:17:33.0828
G0637766 09:09:50 11:06:38.1886 -02:43:10.2684
G0644398 09:11:01 11:07:28.6963 +03:48:08.9928
G0662623 09:12:10 11:08:03.9257 +02:00:13.7196
G0610069 09:13:20 11:08:21.731 +00:49:21.72
G0687196 09:14:29 11:08:43.7292 +00:27:27.5796
G0685235 09:15:38 11:09:46.2708 +00:48:49.2624
G0489553 09:16:48 11:09:48.5266 +01:25:23.2644
G0707360 09:17:57 11:10:33.3874 -00:34:58.2888
G0711373 09:19:06 11:11:00.5969 -00:53:34.7676
G0739801 09:20:18 11:11:16.3661 -06:16:03.3168
G0740915 09:21:29 11:11:16.9298 -00:49:27.75
G1052029 09:22:38 11:13:37.489 -01:57:20.5488
G0569482 09:23:48 11:14:00.6043 -00:20:11.1948
G0810723 09:25:00 11:14:39.1478 -05:18:24.5016
G1070206 09:26:09 11:14:42.1471 -03:48:51.5016
G0662104 09:27:19 11:15:57.8614 -02:10:14.304
G0203483 09:28:28 11:16:00.0074 -03:46:47.3052
G0726560 09:29:37 11:16:06.6761 -02:52:10.3008
GCN Circular 27212
Subject
LIGO/Virgo S200224ca: No Counterparts in DDOTI/OAN Optical Observations
Date
2020-02-25T22:12:02Z (6 years ago)
From
Simone Dichiara at UMCP/NASA/GSFC <dichiara@umd.edu>
Simone Dichiara (GSFC/UMD), Eleonora Troja (GSFC/UMD), Alan M. Watson
(UNAM), Nat Butler (ASU), Margarita Pereyra (UNAM), William H. Lee (UNAM),
Alexander Kutyrev (GSFC/UMD), Rosa L. Becerra (UNAM), Diego Gonzalez
(UNAM), and Tanner Wolfram (ASU) report:
We observed LIGO/Virgo S200224ca (Valsan et al, GCN Circ. 27184) with the
DDOTI/OAN wide-field imager at the Observatorio Astronomico Nacional on
Sierra San Pedro Martir (http://ddoti.astroscu.unam.mx) on the night of
2020-02-25 UTC.
We tiled the LVC localization with two pointings centered on 11:35:23.26
-6:08:15.3 and 11:42:35.81 -11:48:03.3 (J2000). The combined
field covers about 135 square degrees and includes about 83% of the
probability in the current BAYESTAR map.
We observed from 2020-02-25 05:32 UTC to 2020-02-25 11:55 UTC (from 7.17 to
13.55 hours after the event) obtaining exposures of 123 to 155 minutes
across the field in the w filter. We calibrate our images against the APASS
catalog. The 10-sigma limiting magnitude is w = 20.0
Comparing our observations to the USNO-B1 and PanSTARRS PS1 DR2 catalogs we
detect no uncatalogued sources within the observed field to our 10-sigma
limit.
We thank the staff of the Observatorio Astronomico Nacional in San Pedro
Martir.
GCN Circular 27211
Subject
LIGO/Virgo S200224ca: GRAWITA-Campo Imperatore observations.
Date
2020-02-25T21:25:28Z (6 years ago)
From
Fiore De Luise at INAF-Osservatorio Astro. d'Abruzzo <fiore.deluise@inaf.it>
F. De Luise, P. Tedesco, N. Napoleone (INAF- OAAb), A. Rossi (INAF-OAS), M.
Dolci, G. Valentini, M. Cantiello, A. Di Cianno, A. Valentini, L.P.
Pacinelli (INAF- OAAb), M. Fiaschi (MFC Elettronica), G. Greco (Univ.
Urbino), E. Cappellaro (INAF-OA Pd), P. D'Avanzo(INAF- OABr), A. Grado
(INAF-OA Capodimonte), and E. Brocato (INAF- OAAb and OAR), report on
behalf of GRAWITA:
We carried out observations of the LIGO/Virgo trigger GW S200224ca (GCN
Circ. #27184) using the INAF-OAAb 0.9m Schmidt Telescope of the INAF -
Astronomical Observatory of Abruzzo located at 2150 meters o.s.l. at Campo
Imperatore (Italy) and equipped with a 4096x4096 CCD covering a field of
view of 1.15��1.15 square degrees.
Due to weather conditions, only three pointings were made covering an area
of nearly 4 square degrees; a containment probability of ~ 8 % of the 50%
credible region was captured. The pointing sequence was generated using the
GWsky script (G. Greco, https://github.com/ggreco77/GWsky), starting from
the high probability region of the bayestar skymap and taking into account
the airmass and relative density of nearby galaxies at the distance of 1585
+/- 331 Mpc.
The total exposure time for each image was 3x180 sec. The observations were
taken with the r-Sloan band on 2020-02-24 starting at 23:47:37.0 UT, about
one hour after the GW detection (i.e. 2020-02-24 22:22:34.406 UTC). The
estimated limiting magnitude in r-Sloan is about 21.5 mag.
Hereafter the log of the observations.
| RA (J2000) | Dec (J2000) | UT time | filter | exposure time|
| 11:43:50.29 | -07:49:10 | 2020-02-24T23:47:37.0 | r-sloan | 3x180 sec |
| 11:35:44.35 | -07:49:10 | 2020-02-25T00:04:09.6 | r-sloan | 3x180 sec |
| 11:39:47.98 | -07:49:35 | 2020-02-25T00:20:44.8 | r-sloan | 3x180 sec |
The analysis of images is ongoing.
--------------------------------------------
De Luise Fiore, PhD
INAF - Osservatorio Astronomico d'Abruzzo
Via Mentore Maggini, s.n.c.
64100 - TERAMO
Tel +39-0861-439712
Fax +39-0861-439740
--------------------------------------------
GCN Circular 27205
Subject
LIGO/Virgo S200224ca: Subaru/Hyper Suprime-Cam follow-up observations
Date
2020-02-25T16:17:36Z (6 years ago)
From
Takayuki Ohgami at Konan University <t-ohgami@konan-u.ac.jp>
T. Ohgami, N. Tominaga (Konan U.),
T. Morokuma (U. Tokyo),
T. Terai, Y. Takagi, K. Yanagisawa, M. Yoshida (NAOJ),
H. Onozato (U. Hyogo),
M. Sasada (Hiroshima U.),
M. Tanaka (Tohoku U.),
Y. Utsumi (Stanford/SLAC),
on behalf of J-GEM collaboration
We report optical follow-up observations for a high probability area of S200224ca (LIGO Scientific Collaboration and the Virgo Collaboration, GCN #27184) with Hyper Suprime-Cam (HSC) attached to 8.2-m Subaru Telescope. Subaru/HSC has a circular field-of-view of 1.7 deg^2.
We performed HSC-r2 and HSC-z band imaging observations on 2020-02-25 UT. We start the first exposure at 10:43 UT, which corresponds to 12.3 hours after the GW detection. The exposure time per frame was 30 sec. We covered 82.5% of probability region with 60 pointings of the HSC. We revisited each pointing twice in each band. The estimated limiting magnitudes in HSC-r2 and HSC-z band are about 24.8 mag and 23.5 mag, respectively. Detailed analysis is ongoing, and further follow-up observations are planned.
We thank Subaru's staff for making this observation.
The central coordinates of the observed regions are as follows:
JGEM30716 11:40:18.75 -14:28:39.0
JGEM29691 11:34:41.25 -12:01:28.9
JGEM28923 11:31:52.50 -10:11:59.7
JGEM30973 11:43:07.50 -15:05:41.2
JGEM29948 11:37:30.00 -12:38:08.3
JGEM28154 11:29:03.75 -08:23:07.9
JGEM29179 11:34:41.25 -10:48:24.9
JGEM30204 11:40:18.75 -13:14:52.9
JGEM28411 11:31:52.50 -08:59:21.5
JGEM30461 11:43:07.50 -13:51:43.0
JGEM29436 11:37:30.00 -11:24:54.6
JGEM27642 11:29:03.75 -07:10:50.7
JGEM26874 11:26:15.00 -05:22:45.8
JGEM28667 11:34:41.25 -09:35:38.6
JGEM30717 11:45:56.25 -14:28:39.0
JGEM29692 11:40:18.75 -12:01:28.9
JGEM27899 11:31:52.50 -07:46:57.8
JGEM30974 11:48:45.00 -15:05:41.2
JGEM28924 11:37:30.00 -10:11:59.7
JGEM29949 11:43:07.50 -12:38:08.3
JGEM27130 11:29:03.75 -05:58:45.0
JGEM26362 11:26:15.00 -04:10:53.5
JGEM28155 11:34:41.25 -08:23:07.9
JGEM30205 11:45:56.25 -13:14:52.9
JGEM29180 11:40:18.75 -10:48:24.9
JGEM27387 11:31:52.50 -06:34:46.5
JGEM26618 11:29:03.75 -04:46:48.7
JGEM28412 11:37:30.00 -08:59:21.5
JGEM30462 11:48:45.00 -13:51:43.0
JGEM29437 11:43:07.50 -11:24:54.6
JGEM25850 11:26:15.00 -02:59:07.8
JGEM27643 11:34:41.25 -07:10:50.7
JGEM30718 11:51:33.75 -14:28:39.0
JGEM28668 11:40:18.75 -09:35:38.6
JGEM29693 11:45:56.25 -12:01:28.9
JGEM26875 11:31:52.50 -05:22:45.8
JGEM26106 11:29:03.75 -03:34:60.0
JGEM27900 11:37:30.00 -07:46:57.8
JGEM29950 11:48:45.00 -12:38:08.3
JGEM28925 11:43:07.50 -10:11:59.7
JGEM27131 11:34:41.25 -05:58:45.0
JGEM26363 11:31:52.50 -04:10:53.5
JGEM28156 11:40:18.75 -08:23:07.9
JGEM30206 11:51:33.75 -13:14:52.9
JGEM29181 11:45:56.25 -10:48:24.9
JGEM27388 11:37:30.00 -06:34:46.5
JGEM28413 11:43:07.50 -08:59:21.5
JGEM29438 11:48:45.00 -11:24:54.6
JGEM26619 11:34:41.25 -04:46:48.7
JGEM25851 11:31:52.50 -02:59:07.8
JGEM27644 11:40:18.75 -07:10:50.7
JGEM29694 11:51:33.75 -12:01:28.9
JGEM28669 11:45:56.25 -09:35:38.6
JGEM26876 11:37:30.00 -05:22:45.8
JGEM26107 11:34:41.25 -03:34:60.0
JGEM27901 11:43:07.50 -07:46:57.8
JGEM28926 11:48:45.00 -10:11:59.7
JGEM27132 11:40:18.75 -05:58:45.0
JGEM28157 11:45:56.25 -08:23:07.9
JGEM27389 11:43:07.50 -06:34:46.5
GCN Circular 27199
Subject
LIGO/Virgo S200224ca: No counterpart candidates in Fermi-LAT observations
Date
2020-02-25T10:25:01Z (6 years ago)
From
Lorenzo Scotton at CNRS/IN2P3/LUPM <lorenzoscotton@live.it>
M. Crnogorcevic (Univ. of Maryland & NASA/GSFC), L. Scotton (CNRS/IN2P3/LUPM),
N. Di Lalla (Stanford University), M. Axelsson (KTH & Stockholm Univ),
E. Bissaldi (Politecnico & INFN Bari), D. Kocevski (NASA/MSFC),
N. Omodei (Stanford Univ.) and F. Longo (University and INFN, Trieste)
report on behalf of the Fermi-LAT Collaboration:
We have searched data collected by the Fermi Large Area Telescope (LAT) on
February 24, 2020, for possible high-energy (E > 100 MeV) gamma-ray emission in
spatial/temporal coincidence with the LIGO/Virgo trigger S200224ca (GCN 27184).
We define "instantaneous coverage" as the integral over the region of the LIGO
probability map that is within the LAT field of view at a given time, and "cumulative
coverage" as the integral of the instantaneous coverage over time.
The Fermi Gamma-ray Space Telescope was passing through the South Atlantic
Anomaly (SAA) at the time of the trigger (T0 = 2020-02-24 22:22:34.406 UTC).
During SAA passages both the LAT and the Gamma-ray Burst Monitor (GBM) do not
collect data due to the high charged particle background in this region. The LAT
resumed taking data upon exiting the SAA at roughly T0 + 0.5 ks. At that time the
instantaneous coverage was 5% of the LIGO probability map, and reached
almost 100% cumulative coverage at approximately T0 + 6.4 ks.
We performed a search for a transient counterpart within the observed region of
the 90% contour of the LIGO map in a fixed time window from T0 + 0.5 ks to T0 + 10 ks.
No significant new sources are found.
We also performed a search which adapted the time interval of the analysis to the
the exposure of each region of the sky, and no additional excesses were found.
Energy flux upper bounds for the fixed time interval between 100 MeV and 1 GeV
for this search vary between 2.6 e-10 and 4.5 e-10 [erg/cm^2/s].
The Fermi-LAT point of contact for this event is
Lorenzo Scotton (lorenzo.scotton@lupm.in2p3.fr).
The Fermi-LAT is a pair conversion telescope designed to cover
the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between
NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.
GCN Circular 27195
Subject
LIGO/Virgo S200224ca: upper limits from AGILE/GRID observations
Date
2020-02-25T07:14:51Z (6 years ago)
From
Francesco Verrecchia at SSDC,INAF-OAR <francesco.verrecchia@ssdc.asi.it>
F. Verrecchia (SSDC, and INAF/OAR), A. Ursi (INAF/IAPS), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano
(INAF/IAPS), F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), A. Bulgarelli, V.
Fioretti, N. Parmiggiani (INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), F.
Longo (Univ. Trieste, and INFN Trieste), report on behalf of the AGILE Team:
In response to the LIGO-Virgo GW event S200224ca at T0 = 2020-02-24
22:22:34.378 UTC a preliminary analysis of the AGILE exposure at T0 shows
that the Gamma-Ray Imaging Detector (GRID) exposure covered less than 10%
of the 90% c.l. localization region (LR).
We performed an analysis of the GRID data in the energy range 50 MeV -
10 GeV over time intervals before and after T0, where good exposure of
the S200224ca 90% c.l. LR was available.
No candidate gamma-ray transient was detected.
The following preliminary GRID values of 3-sigma upper limit (UL) are
obtained:
from 2.1e-07 to 2.1e-06 erg cm^-2 s^-1, with exposure of about 65% of the
LR over the time interval (T0 - 100 s ; T0 s);
These measurements were obtained with AGILE observing a large portion of
the sky in spinning mode. Additional analysis of AGILE data is in progress.
GCN Circular 27192
Subject
LIGO/Virgo S200224ca: not observable by Fermi-GBM
Date
2020-02-25T04:40:26Z (6 years ago)
From
Cori Fletcher at USRA <cfletcher@usra.edu>
C. Fletcher (USRA) reports on behalf of the Fermi-GBM Team and the GBM-LIGO/Virgo group
At the time of S200224ca, Fermi was passing through the South Atlantic Anomaly from 16.8 minutes prior to 6.8 minutes after the trigger time; therefore the GBM detectors were disabled.
GCN Circular 27190
Subject
LIGO/Virgo S200224ca: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
Date
2020-02-25T01:18:52Z (6 years ago)
From
Maeve Doyle at U College Dublin, Ireland <maeve.doyle.1@ucdconnect.ie>
M. Doyle (UCD, Ireland)
V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)
J. Rodi (IAPS-Roma, Italy)
A. Coleiro (APC, France)
S. Mereghetti (INAF IASF-Milano, Italy)
on behalf of the INTEGRAL multi-messenger collaboration:
https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration
Using INTEGRAL/SPI-ACS realtime data (following [1]) we have performed
a search for a prompt gamma-ray counterpart of S200224ca (GCN 27184).
At the time of the event (2020-02-24 22:22:34 UTC, hereafter T0),
INTEGRAL was operating in nominal mode. The peak of the event
localization probability was at an angle of 100 deg with respect to
the spacecraft pointing axis. This orientation implies strongly
suppressed (4.2% of optimal) response of ISGRI, strongly suppressed
(13% of optimal) response of IBIS/Veto, and somewhat suppressed (58%
of optimal) response of SPI-ACS.
The background within +/-300 seconds around the event was very stable
(excess variance 1.1).
We have performed a search for any impulsive events in INTEGRAL SPI-
ACS (as described in [2]) data.
We do not detect any significant counterparts and estimate a 3-sigma
upper limit on the 75-2000 keV fluence of 3e-07 erg/cm^2 (within the
50% probability containment region of the source localization) for a
burst lasting less than 1 s with a characteristic short GRB spectrum
(an exponentially cut off power law with alpha=-0.5 and Ep=600 keV)
occurring at any time in the interval within 300 s around T0. For a
typical long GRB spectrum (Band function with alpha=-1, beta=-2.5, and
Ep=300 keV), the derived peak flux upper limit is ~2.4e-07 (8.4e-08)
erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range.
For the mean reported distance 1585.0 Mpc this corresponds to the
limit on the total isotropic equivalent energy in 1 s of 9e+49 erg
for the short GRB spectrum and for a long GRB spectrum isotropic
equivalent luminosity in 1 s (8 s) of 7.1e+49 erg/s (2.5e+49 erg/s)
We report for completeness and in order of FAP, all excesses
identified in the search region. We find 2 likely background
excesses:
T-T0 | scale | S/N | luminosity ( x 1e+49 erg/s) | FAP
-30.7 | 0.3 | 3.7 | 20.5 +/- 5.02 +/- 4.52 | 0.519
-32.7 | 0.7 | 3.1 | 10.9 +/- 3.27 +/- 2.41 | 0.934
Note that FAP estimates (especially at timescales above 2s) may be
possibly further affected by enhanced non-stationary local background
noise. This list excludes any excesses for which FAP is close to
unity.
All results quoted are preliminary.
This circular is an official product of the INTEGRAL Multi-Messenger
team.
[1] Savchenko et al. 2017, A&A 603, A46
[2] Savchenko et al. 2012, A&A 541A, 122S
GCN Circular 27188
Subject
LIGO/Virgo S200224ca: Coverage and upper limits from MAXI/GSC observations
Date
2020-02-25T00:31:00Z (6 years ago)
From
Motoko Serino at RIKEN/MAXI <motoko@crab.riken.jp>
M. Serino, S. Sugita (AGU),
N. Kawai (Tokyo Tech), H. Negoro (Nihon U.),
M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi, R. Takagi (Nihon U.),
T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, H. Nishida, A. Yoshida (AGU),
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.),
M. Shidatsu (Ehime U.), M. Oeda, K. Shiraishi (Tokyo Tech),
S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, R. Shimomukai, M. Tominaga (JAXA),
Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.),
H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.),
M. Yamauchi, S. Iwahori, Y. Kurihara, K. Kurogi, K. Miike (Miyazaki U.),
T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC)
report on behalf of the MAXI team:
We examined MAXI/GSC all-sky X-ray images (2-20 keV)
after the LVC trigger S200224ca at 2020-02-24 22:22:34.406 UTC (GCN 27184).
At the trigger time of S200224ca, the high-voltage of MAXI/GSC was off,
and it was turned on at T0+12 sec (+0.2 min).
The first one-orbit (92 min) scan observation with GSC after the event covered 100%
of the 90% credible region of the bayestar skymap from 22:25:27 to 22:27:57 UTC (T0+173 to T0+323 sec).
No significant new source was found in the region in the one-orbit scan observation.
A typical 1-sigma averaged upper limit obtained in one scan observation
is 20 mCrab at 2-20 keV.
If you require information about X-ray flux by MAXI/GSC at specific coordinates,
please contact the submitter of this circular by email.
GCN Circular 27187
Subject
LIGO/Virgo S200224ca: upper limits from AGILE/MCAL observations
Date
2020-02-25T00:30:51Z (6 years ago)
From
Alessandro Ursi at INAF/IAPS <alessandro.ursi@gmail.com>
A. Ursi (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, G.
Piano (INAF/IAPS), F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), A.
Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna), M. Pilia
(INAF/OA-Cagliari), F. Longo (Univ. Trieste, and INFN Trieste), report on
behalf of the AGILE Team:
In response to the LIGO/Virgo GW event S200224ca at T0 = 2020-02-24
22:22:34.378 (UT), a preliminary analysis of the AGILE minicalorimeter
(MCAL) triggered data found no event candidates within a time interval
covering -/+ 15 sec from the LIGO/Virgo T0.
At the T0, the S200224ca 90% c.l. localization region (LR) was totally
accessible to the AGILE/MCAL.
Three-sigma upper limits (ULs) are obtained for a 1 s integration time at
different celestial positions within the accessible S200224ca LR, from a
minimum of 2.17E-06 erg cm^-2 to a maximum of 6.32E-06 erg cm^-2 (assuming
as spectral model a single power-law with photon index 1.5).
An independent procedure based on photon counting statistics provides UL
fluences in the range 0.4-1 MeV, for a 300 us integration time, from a
minimum of 1.44E-08 erg cm^-2 to a maximum of 4.39E-08 erg cm^-2.
The AGILE/MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the
energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress.
GCN Circular 27186
Subject
LIGO/Virgo S200224ca: Global MASTER-Net observations report
Date
2020-02-25T00:08:15Z (6 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov, D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
H.Levato
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova
(Irkutsk State University, API),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko
(Blagoveschensk Educational State University)
MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the LIGO/Virgo S200224ca errorbox 325 sec after trigger time at 2020-02-24 22:27:59 UT, with upper limit up to 18.2 mag. The observations began at zenith distance = 53 deg. The sun altitude is -53.7 deg.
The galactic latitude b = 49 deg., longitude l = 277 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/ligo_1.php?id=11357
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
347 | 2020-02-24 22:27:51 | MASTER- | (11h 42m 01.93s , -09d 53m 27.1s) | C | 60 | 19.6 |
347 | 2020-02-24 22:27:51 | MASTER- | (11h 34m 56.14s , -09d 54m 43.0s) | C | 60 | 19.6 |
355 | 2020-02-24 22:27:59 | MASTER-Kislovodsk | (11h 34m 39.10s , -09d 50m 29.2s) | C | 60 | 18.2 |
445 | 2020-02-24 22:27:59 | MASTER-Kislovodsk | (11h 34m 39.10s , -09d 50m 29.1s) | C | 240 | 17.9 | Coadd
355 | 2020-02-24 22:27:59 | MASTER-Kislovodsk | (11h 43m 03.44s , -10d 17m 30.1s) | C | 60 | 17.8 |
437 | 2020-02-24 22:29:10 | MASTER- | (11h 42m 04.88s , -09d 52m 42.1s) | C | 80 | 19.7 |
437 | 2020-02-24 22:29:10 | MASTER- | (11h 34m 59.09s , -09d 53m 58.4s) | C | 80 | 19.7 |
446 | 2020-02-24 22:29:19 | MASTER-Kislovodsk | (11h 34m 36.01s , -09d 51m 35.1s) | C | 80 | 16.8 |
446 | 2020-02-24 22:29:19 | MASTER-Kislovodsk | (11h 43m 00.26s , -10d 18m 36.8s) | C | 80 | 16.9 |
546 | 2020-02-24 22:30:50 | MASTER- | (11h 41m 58.48s , -09d 53m 34.6s) | C | 100 | 19.8 |
546 | 2020-02-24 22:30:50 | MASTER- | (11h 34m 52.68s , -09d 54m 51.1s) | C | 100 | 19.8 |
557 | 2020-02-24 22:31:00 | MASTER-Kislovodsk | (11h 34m 42.29s , -09d 51m 09.1s) | C | 100 | 15.6 |
557 | 2020-02-24 22:31:00 | MASTER-Kislovodsk | (11h 43m 06.46s , -10d 18m 10.4s) | C | 100 | 15.8 |
781 | 2020-02-24 22:34:24 | MASTER-Kislovodsk | (11h 34m 40.04s , -09d 37m 01.3s) | C | 140 | 15.9 |
781 | 2020-02-24 22:34:24 | MASTER-Kislovodsk | (11h 43m 04.25s , -10d 04m 06.0s) | C | 140 | 15.8 |
820 | 2020-02-24 22:34:59 | MASTER- | (11h 42m 01.97s , -09d 40m 05.0s) | C | 150 | 19.9 |
820 | 2020-02-24 22:34:59 | MASTER- | (11h 34m 56.44s , -09d 41m 21.8s) | C | 150 | 19.9 |
966 | 2020-02-24 22:37:10 | MASTER-Kislovodsk | (11h 44m 13.13s , -09d 46m 09.6s) | C | 180 | 14.8 |
966 | 2020-02-24 22:37:10 | MASTER-Kislovodsk | (11h 35m 57.55s , -09d 19m 57.4s) | C | 180 | 14.2 |
1005 | 2020-02-24 22:37:48 | MASTER- | (11h 42m 05.26s , -09d 40m 50.2s) | C | 180 | 19.5 |
1005 | 2020-02-24 22:37:48 | MASTER- | (11h 34m 59.65s , -09d 42m 07.0s) | C | 180 | 19.9 |
1167 | 2020-02-24 22:40:31 | MASTER-Kislovodsk | (11h 44m 12.27s , -09d 45m 20.2s) | C | 180 | 13.1 |
1167 | 2020-02-24 22:40:31 | MASTER-Kislovodsk | (11h 35m 56.78s , -09d 19m 09.3s) | C | 180 | 13.3 |
1204 | 2020-02-24 22:41:08 | MASTER- | (11h 42m 01.99s , -09d 39m 27.2s) | C | 180 | 19.5 |
1204 | 2020-02-24 22:41:08 | MASTER- | (11h 34m 56.37s , -09d 40m 44.3s) | C | 180 | 19.9 |
1368 | 2020-02-24 22:43:52 | MASTER-Kislovodsk | (11h 44m 19.63s , -09d 46m 23.8s) | C | 180 | 16.4 |
1368 | 2020-02-24 22:43:52 | MASTER-Kislovodsk | (11h 36m 04.16s , -09d 20m 13.2s) | C | 180 | 16.1 |
1404 | 2020-02-24 22:44:27 | MASTER- | (11h 42m 01.96s , -09d 40m 48.7s) | C | 180 | 19.5 |
1404 | 2020-02-24 22:44:27 | MASTER- | (11h 34m 56.31s , -09d 42m 06.0s) | C | 180 | 19.9 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 27185
Subject
LIGO/Virgo S200224ca: Upper limits from IceCube neutrino searches
Date
2020-02-24T22:53:09Z (6 years ago)
From
Raamis Hussain at IceCube <raamis.hussain@icecube.wisc.edu>
IceCube Collaboration (http://icecube.wisc.edu/) reports:
Searches [1,2] for track-like muon neutrino events detected by IceCube
consistent with the sky localization of gravitational-wave candidate
S200224ca
in a time range of 1000 seconds [3] centered on the alert event time
(2020-02-24 22:14:14.406 UTC to 2020-02-24 22:30:54.406 UTC) have been
performed.
During this time period IceCube was collecting good quality data.
No significant track-like events are found in spatial coincidence of
S200224ca calculated from the map circulated in the 2-Preliminary notice.
IceCube's sensitivity assuming an E^-2 spectrum (E^2 dN/dE) to neutrino
point sources within the locations spanned by the 90% spatial containment
of S200224ca ranges from 0.029 to 0.206 GeV cm^-2 in a 1000 second
time window.
The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector
operating at the geographic South Pole, Antarctica. The IceCube realtime
alert point of contact can be reached at roc@icecube.wisc.edu
[1] Bartos et al. arXiv:1810.11467 (2018) and Countryman et
al.arXiv:1901.05486 (2019)
[2] PoS(ICRC2019)918 and Braun et al., Astroparticle Physics 29, 299 (2008)
[3] Baret et al., Astroparticle Physics 35, 1 (2011)
GCN Circular 27184
Subject
LIGO/Virgo S200224ca: Identification of a GW compact binary merger candidate The LIGO Scientific Collaboration and the Virgo Collaboration
Date
2020-02-24T22:53:00Z (6 years ago)
From
Vinaya Valsan at U. of Wisconsin Milwaukee <vvalsan@uwm.edu>
We identified the compact binary merger candidate S200224ca during
real-time processing of data from LIGO Hanford Observatory (H1),LIGO
Livingston Observatory (L1), and Virgo Observatory (V1) at 2020-02-24
22:22:34.406 UTC (GPS time: 1266618172.406). The candidate was found
by the PyCBC Live [1], CWB [2], GstLAL [3], MBTAOnline [4] ,and SPIIR [5]
analysis pipelines.
S200224ca is an event of interest because its false alarm rate, as
estimated by the online analysis, is 1.6e-11 Hz, or about one in 1e3
years. The event's properties can be found at this URL:
https://gracedb.ligo.org/superevents/S200224ca
The classification of the GW signal, in order of descending
probability, is BBH (>99%), Terrestrial (<1%), BNS (<1%), NSBH
(<1%), or MassGap (<1%).
Assuming the candidate is astrophysical in origin, the probability
that the lighter compact object has a mass < 3 solar masses (HasNS) is
<1%. Using the masses and spins inferred from the signal, the
probability of matter outside the final compact object (HasRemnant) is
<1%.
Two sky maps are available at this time and can be retrieved from the
GraceDB event page:
* bayestar.fits.gz,0, an initial localization generated by BAYESTAR
[6], distributed via GCN notice about 3 minutes after the candidate
event time.
* bayestar.fits.gz,1, an initial localization generated by BAYESTAR
[6], distributed via GCN notice about 10 minutes after the candidate
event time.
The preferred sky map at this time is bayestar.fits.gz,1. For the
bayestar.fits.gz,1 sky map, the 90% credible region is well fit by an
ellipse with an area of 73 deg2 described by the following DS9 region
(right ascension, declination, semi-major axis, semi-minor axis,
position angle of the semi-minor axis):
icrs; ellipse(11h38m42s, -09d20m21s, 9d, 3d, 68d)
Marginalized over the whole sky, the a posteriori luminosity distance
estimate is 1585 +/- 331 Mpc (a posteriori mean +/- standard
deviation).
For further information about analysis methodology and the contents of
this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https://emfollow.docs.ligo.org/userguide/>.
[1] Nitz et al. PRD 98, 024050 (2018)
[2] Klimenko et al. PRD 93, 042004 (2016)
[3] Messick et al. PRD 95, 042001 (2017)
[4] Adams et al. CQG 33, 175012 (2016)
[5] Qi Chu, PhD Thesis, The University of Western Australia (2017)
[6] Singer & Price PRD 93, 024013 (2016) [7] Singer & Price PRD 93,
024013 (2016)